Power swing crane



July 25, 1939. R, K, HAT 2,161,026

POWER SWING CRANE Filed Spt. 24, 19158 2 Sheets-Sheet 1,

r INVENTOR B fi zdzz/z/hz-z.

A TTORNE V61 annea ing 25, 1939 ammo PATENT, 1 [OFFICE rowan swnva CRANE Ronald x. Hatch, Highland Park, Mich, alslgnor to Gar Wood Industri -Michlgan The present invention relates to cranes, and in particular provides a crane of the vehicle carried type, embodying improved power actuated means for effecting a swinging movement of the boom.

of the crane.

Principal objects of the present invention are to provide a crane of the above generally indicated type, characterized as including improved meansfor supporting the inner end of the boom and for effecting swinging movements thereof; to

provide such a st cture in which the swinging mechanism for the boom is arranged for power actuation: to provide such an arrangement characterized as including an improvedbearingrelal5 tionship, the bearings being interposed between the connection to the end of the boom-and, the

connection to the power element; to provide such a construction wherein the inner end of the boom is provided with a head, rotatably supported upon 20 a cooperating structure, andarranged for .con-

nection to a source of power; to provide such a construction in which the head forms a closure for a housing adapted to be substantially filled with lubricant so as to continuously'lubricate the 25 power actuating element associated with the head; and in which'adequate means are provided to vent the housing; and to provide such a construction wherein the, head associated with the boom is fitted over a stationarily supported 30 column, having a housing formed at its base, the head acting to enclose the-upper portion of the housing. e I

, With the above, as well as other and more de-l tailed objects in view, which appear in the ,de-. 35 scription and inthe appended claims, a preferred but illustrative embodiment of the invention is shown in the accompanying drawings, throughout the several'views of which corresponding reference charactersare used to designate correspond- 40 mg parts, and in which: I

Figure 1 is a view in side elevation of a vehicle-carried crane embodying the invention;

Fig.2 is a rear'view corresponding to Fig. 1, but showing, in dottedlines, the boom swunsto 5 ,oneside;

. Fig; 3 is a detail view, taken along the line 3-4 of Fig. 2; and 4 Fig. 4 is .'an enlarged view, taken along the line 4'|-of Fig.1.

In a general sense, the invention is directed to the combination in a crane, having means for controlling the hoisting movements thereof, of a power actuated unit for the inner end of the boom, whereby thelatter is supported and 55 whereby it may be swung through a desired angle.

' ing and lowering movements of the outer end of Application September :4, 1938, Serial No, 231,452

.4 Claims. (01. 212-68) 1 As will appear from a complete understanding of the invention, the 'unit itself may be constructed in a variety of different ways within the spirit and scope of the invention and may be embodied in cranes intended for widely differingapplica- 5 'tions. The improvements have particular utility 4 in connection with cranes of the so-called vehiclecarried type, and, in an illustrative but not in a limiting sense. are so disclosed herein.- 1 e Referring first to Figs. 1 and 2, the crane con- 16 struction selected to exemplify the invention comprisesan A-frame I! which is supported'upo'n and rises substantially vertically from the frame I! of a supporting vehicle 14; a boom it which 1 carries a hook Id at its outer end and is connected 15 at its inner end to the hereinafter described im-- proved unit and suitable mechanism, including the winch 22, for eifecting the hoisting and lowering movements of the hook I8 and the raisthe boom it h 20 It will beunder'sto'od that the A-=frame Ill may be of usual construction, and comprises, in the illustrated arrangement, the pair of legs 24 and 26, which are suitably braced together and are 25 supported at their lower ends upop cross-members 48 which form the crane base and which are in turn supported directly upon the vehicle frame. The frame I0 is bracedover the cab to the front of the supporting vehicle ll by meansof'the lines 28 which are connected to the front end of, he vehicle frame and which are-also connected to the A+frame I0 through the 'forwardly extending frame members". The just described construction of the supporting structure for the crane is extremely advantageous, in that it occupies only a relatively small percentage of the space behind the cab, leaving a relatively large portion thereof available for load carrying purposes.

,It will beunderstoo'd'that the winch 21 is con- 40 nected to .thehook I. through one or. more cables 1 32, which afe trainedover 'a pulley or pulleys 34 at the outer end ofv the crane, a pulley 38 at the inner end, a pulley ll carried by the hereinafter described unit 20; and one or more pulleys, such 5.

as 40 and ll, which are mounteddn thevA-frame. In addition, the winch is connected to raise and lower the boom through services of cables including the cables M. It will'further be understood that the winch is selectively. controllable,

:so as to independently raise and lowerfthe hook and-raise and lower the boom.

, In addition to the foregoing features, it is preferred tolprovide the crane wlthslidable outriggers and m, which may be slid transversely-through the crane base It, between the extended and the retracted positions. The outrigger 4C is shownln its extended position, in

which it is braced by the tubular telescopic brace 50. The companion outrigger a is shown in its retracted position, in which its associated tubular; telescopic brace 56 is in its retracted or shortened condition. The telescopic braces 50 and 56 may be made of two or'more tubes, as will be understood. a

It is also preferred to provide the outriggers with jacks 52- and 54, which give vertical support to-the outer ends thereof. The Jacks 52 and 54' are illustrated as being swingably connected to the outer ends of the associated outriggers l8 and l6a,-respectively; so thatthey may be swung upwardly to retracted position, or, alternatively, may be disconnected therefrom and carried upon the vehicle. It will further be understood that during travel of the vehicle, the outriggers nor-- mally occupythe retracted positionshown in connection with the outrigger a,- so that they do not add-materially to the overall width of the vehicle.

It will be understood that in operation, the above generally described crane may be utilized for widely varying purposes. Typical duties include the removing of a load from the vehicle ll to'one side of thereafthereof or vice versa, and

boom is swung. In addition, both the vertical the transferring of a load from a position at one side of the vehicle I to a position at the other side. During the course of such operations, the supporting mechanism for the inner'end of the boom is subjected to extremely severe operating loads, since the load reactions thereon have substantial vertical components and also have substantial radial components, which latter components continuously vary in direction as the and the radial components of the load are subject to abrupt changes, caused for example when the' load is either engaged or disengaged by the hook ll. Such extreme service conditions have given rise to considerable difficulty in the,design of a swinging and supporting mechanism for the inner end of the boom,'which is reliable and durable in use and which must the same time be readily and economically manufactured, installed, and

serviced when necessary. The present improved unit 20 has been found in' practice to solvethe above as well as other dimculties infan extremely effective and simple manner. 1 Referring now particularly'to Figs. 3 and 4, the unit I. for supporting the inner end of the boom I! and for ng the boom comprises generally a base structure I, adapted to be bolted or otherwise directly secured to the frame of the vehicle I or to the crane structure or to other suitable supporting structure.' The frame '9 is of gener-' ally'circular form, and is provided with an upwardly extending annular wall 62, which, with thelower side or bottom 86 of the base, defines an upwardly presenting cup-like housing. A portion of the wall, indicated at 64, is extended radially outwardly to accommodate a driving worm.

The bottomv 86 of the base 80 is upwardly ex-- tended adjacent the center of the base and constitutes a substantially vertical tubular bearing column v The base "is surmounted by a head 1., which is ,rotatably mounted thereon by ,ball bearing units I2 and ll. The inner race of the ball bearing unit 12, which is adapted to sustain radial loads, is fitted upon the upper portion of the column 68 and the lower face thereof rests upon a shoulder II formed on th column 68. The

.of the Just mentioned race.

cal portion 15 of the head 10.. The outer race of the lower bearing unit 14 is received in a cylindrical portion formed partly within the head and partly within thev worm wheel 8|]. A shoulder 15 formed in the head I0 overlies the upper surface The inner race of outerrace of the unit 12 is received in acyliridrie the unit T4 is fitted over the'standard and rests upon a shoulder 11 thereon. It will be seen, accordin'gly, that the ball bearing unit I4 sustains both thrust and radial loads.

Head III is provided with a flat under surface 88, to which the driving worm wheel 90 is secured. by a plurality of circumferentially arranged cap screws 92. The worm wheel 90 is of generally inverted cup-like form. The unit comprising the head 10 and the worm wheel 90 are maintained in fixed axial position relative to the bearing column 88 by means of the lower ball bearingunit l4 and the imposed thrust loads. A cap plate 94, which is fitted to the end of the bearing column 68 and is secured in place thereon by one or more cap screws 96 closes the end of the column 88 and restrains vertical upward movement of the head Ill. It will be understood'that theflange of the cap plate 96 overlies the upper end of the head 10.

As is described in more detailhereinafter, the inner end of the boom is connected to the head 10, so that rotative movements of the head Ware correspondinglyimparted to the boom and cause a swinging movement thereof. The head 10 is in itself entirely freelycontihuously rotatable relativeto the base 80,50 that the onlylimitations which are imposed on the'angle of swing'of the boom are those which are imposed by the supporting framework of the crane. In practice, the

' present disclosed arrangement has been found to freely accommodate an angle of substantially 180."

The worm wheel 9. is in constant meshing relation with a worm [00, the shaft I02 for which is suitably supported in bearings (not-shown),

formed in the wall of the base 60. It will be understood that the shaft l02' is preferably connected, through a shaft ill, 'to a suitable power take-01f mechanism (not shown) associated with the main vehicle driveshaft gearing, so that the worm I00 and the worm wheel 90 may be rotated by power derived from the vehicle engine. It will further be understood that the previously described winch 22 may be similarly driven through a conventional power take-oil. It will be noticed that in the above described structure the support ingbearings for the rotatable head 10 are interposed between "the point at which the load on the boom i0 is applied andthe point at which the driving power is applied and that the dead sheave '3! is so mounted that the vertical rope lead from less-completely submerged in a bath of lubricant.

In order to seal-oi! the upper and otherwise open surface of the housing constituted by the base til, so as to prevent the escape or suchlubricant I as well as to prevent the entrance. of dirt or other foreignmatter, it is preferred to so form the head I that it acts as a closure for such surface. With this consideration in view, the head I0 is provided with a radially flaring skirt I04, which terminates in, spaced flanges I06 and I08. The flange I06 lies closely adjacent the radially inner face of the wall of the reservoir, and the flange I08 is received 'in a channel shaped recess II2 formed in the outer surface of the wall of the housing. The flanges I00 and I06 deflne between them a channel which is occupied by an upwardly extending flange II4 formed on the housing wall, I

The depending flange I06 is' provided with a beveled under-surface I03 and the upstanding flange H4 is provided with a similar but oppo sitely beveledupper surface I05. The bevel I03 tends to prevent the lubricant in the chamber occupied by the worm and the worm wheel from creeping up into the joint represented by the adjacent surfaces-of the flanges I00 and H4,

-while the second bevel I05 forms an enlarged space or chamber between such flanged surfaces,

which tends to break the adhesion of.the lubricant, and to allow the latter to gravitate back into the chamber- ,With' this relation, it 'will be appreciated that an effective closure for the reservoir is provided, which serves to prevent the entrance thereinto of dirt or other foreign maiterial, and at. the same time permits a spaced veloped within the reservoir during operation of the unit, which heat may tend to develop an ap= preciable oil expansion and air pressure therein, which, if not vented, would tend to force lubricant past the seal, it is preferred to vent the reservoir. In the illustrated arrangement, this is accomplished by providing vent openings I01 and I09 in the wall of the bearing column 68 and in the annular wall of the head I0.

' As will be evident from the drawings, lubrication of the bearings I2 and I4: is provided through. lubricant passages II 3, H3, and H5.

As most clearly appears in Figure 4, the upper portion of the head I0 is provided with a boss- 'like formation II6, the laterally opposite sides whereof are provided with axially projecting trunnions or hinge pins H8. The trunnions II8 rotatably support the spaced legs I20 which are formed at the inner end of the boom I8. With invention has been described in detail, it will be appreciated that various modifications in the form, number, and arrangement of the parts may be made within the spirit and scope of the invention. a

What is claimed is:

1. In a crane having a boom, the combination of a unit for supporting the inner end of the boom and for swinging the boom comprising a supporting base structure, a member rotatably supported on said base, means on said member adapting it to be driven in rotation, means on said member axially-spaced from said first mentioned means adapting said member for connection to the boom, and bearing connections between said base and said member positioned between said first and second means, said bearing connections comprising a pair of axially spaced anti-friction bearings, one located adjacent the boom connection and the other located adjacent the rotational drive.

2. In a crane having a boom, the combination of a unit for supporting the inner end of the boom and for swinging the boom, comprisinga supporting base structure and a head rotatably mounted therein, said head having a skirt and said base having an annular wall, said wall and skirt cooperating to define a substantially enclosed housing, means mounted on one end of said head withinsaid housing for adapting said head to be driven in rotation, additional means on the other end of said head external to said housing for adapting it for connection to 'the' boom, bearingconnections between said head and base interposed between said'flrst and second nientioned means, said bearing connections comprising a bearing column projecting axially from said base, and bearing openings formed in said head receiving said column.

3. In a crane'having a boom, the combination of a unit for supporting the inner end of the boom and for swinging the boom, comprising a base of generally cup-like form having an annular wall and having a bearing column projecting axially, from the base at the center thereof, a

head rotatably supported onsaid base, said head having a radially flaring skirt adapted to cooperate with said wall to define a substantially enclosed housing, means including a worm wheel mounted on said head within said housing for adapting said head to be driven in rotation,-

additionalmeans mounted-on the other end of said head external to said housing for adapting the head to be connected to the boom, and bearing elements positioned in said head between said first and second means for rotative connection to said bearing column. v

' 4. In a crane having a boom, 9. horizontal base having an integrally formed upstanding column, an annular wall on said base surrounding said column in spaced relation, a' head surrounding said column and 'joumaled thereon, a worm .Wheel on the lower end of said head and located in the space between said colum'n and said wall, a skirt on the upper end of said head covering the space between said column and said wall, and means on said head above said skirt for RONALD K. HATCH. 

